Abstract
The upper atmosphere of a planet is a transition region in which energy is transferred between the deeper atmosphere and outer space. Molecular emissions from the upper atmosphere (90–120 km altitude) of Venus can be used to investigate the energetics and to trace the circulation of this hitherto little-studied region. Previous spacecraft1 and ground-based2,3,4 observations of infrared emission from CO2, O2 and NO have established that photochemical and dynamic activity controls the structure of the upper atmosphere of Venus. These data, however, have left unresolved the precise altitude of the emission1 owing to a lack of data and of an adequate observing geometry5,6. Here we report measurements of day-side CO2 non-local thermodynamic equilibrium emission at 4.3 µm, extending from 90 to 120 km altitude, and of night-side O2 emission extending from 95 to 100 km. The CO2 emission peak occurs at ∼115 km and varies with solar zenith angle over a range of ∼10 km. This confirms previous modelling7, and permits the beginning of a systematic study of the variability of the emission. The O2 peak emission happens at 96 km ± 1 km, which is consistent with three-body recombination of oxygen atoms transported from the day side by a global thermospheric sub-solar to anti-solar circulation, as previously predicted8.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Bougher, S. W., Alexander, M. J. & Mayr, H. G. Upper atmosphere dynamics: global circulation and gravity waves. In Venus II: Geology, Geophysics, Atmosphere, and Solar Wind Environment (eds Bougher, S. W. Hunten, D. M. & Philips R. J.) 259–292 (Univ. Arizona Press, Tucson, 1997)
Connes, P. Noxon, J. F., Traub, W. A. & Carleton, N. O2 1Δ emission in the day and night airglow of Venus. Astrophys. J. Lett. 233, L29–L32 (1979)
Crovisier, J. et al. Carbon monoxide emissions at 4.7μm from Venus’ atmosphere. Planet. Space Sci. 54, 1398–1414 (2006)
Lellouch, E. et al. Monitoring of mesospheric structure and dynamics. In Venus II: Geology, Geophysics, Atmosphere, and Solar Wind Environment (eds Bougher, S. W. Hunten, D. M. & Philips R. J.) 295–324 (Univ. Arizona Press, Tucson, 1997)
Drossart, P. et al. Scientific goals for the observation of Venus by VIRTIS on ESA/Venus Express mission. Planet. Space Sci. 10.1016/j.pss.2007.01.03 (in the press)
Lopez-Valverde, M. A., Drossart, P., Carlson, R., Mehlman, R. & Roos-Serote, M. Non-LTE infrared observations at Venus: From NIMS/Galileo to VIRTIS/Venus Express. Planet. Space Sci. 10.1016/j.pss.2007.01.008 (in the press). (2007)
Roldan, C., Lopez-Valverde, M. A., Lopez-Puertas, M. & Edwards, D. P. Non-LTE infrared emissions of CO2 in the atmosphere of Venus. Icarus 147, 11–25 (2000)
Crisp, D. et al. Ground-based near-infrared observations of the Venus nightside: 1.27-μm O2(1Δg) airglow from the upper atmosphere. J. Geophys. Res. 101, 4577–4594 (1996)
Piccioni, G. et al. South-polar features on Venus similar to those near the north pole. Nature 10.1038/nature06209 (this issue).
Titov, D. V. et al. Venus Express science planning. Planet. Space Sci. 54, 1279–1297 (2006)
Lellouch, E. et al. The 2.4–45μm spectrum of Mars observed with the infrared space observatory. Planet. Space Sci. 48, 1393–1405 (2000)
Picard, R. H., Wintersteiner, P. P., Hegblom, E. R. & Richards, E. Remote sensing of discrete stratospheric gravity-wave structure at 4.3-μm from the MSX satellite. Geophys. Res. Lett. 25, 2809–2812 (1998)
Formisano, V., Maturilli, A., Giuranna, M., D’Aversa, E. & Lopez-Valverde, M. A. Observations of non-LTE emission at 4–5 microns with the planetary Fourier spectrometer aboard the Mars Express mission. Icarus 182, 51–67 (2006)
Lopez-Valverde, M. A. & Lopez-Puertas, M. A non-local thermodynamic equilibrium radiative transfer model for infrared emissions in the atmosphere of Mars. 1. Theoretical basis and nighttime populations of vibrational states. J. Geophys. Res. 99, 13093–13115 (1994)
Keating, G. M. et al. Models of Venus neutral upper atmosphere: Structure and composition. Adv. Space Res. 5, 117–171 (1985)
Ohtsuki, S. et al. Ground-based observation of the Venus 1.27-μm O2 airglow. Adv. Space Res. 36, 2038–2042 (2005)
Acknowledgements
We acknowledge the work of the entire Venus Express team of ESA and Astrium, who allowed these data to be obtained. This work is supported by the national space agencies CNES and ASI, and by SFTC in the UK. J.C.G. thanks the FNRS and the PRODEX-ESA program for funding.
Author Contributions P.D. and G.P. have coordinated the work as Principal Investigators of VIRTIS. J.C.G. contributed to the O2 model, L.Z. to the O2 data selection, and M.A.L.-V. to the CO2 model. A.S.-L. and R.H. contributed to the dynamics calculation for Fig. 3. All authors contributed equally to the planning of the work, instrumental calibration and data calibration. F.W.T. and B.B. helped to finalize the paper.
Author information
Authors and Affiliations
Consortia
Corresponding author
Rights and permissions
About this article
Cite this article
Drossart, P., Piccioni, G., Gérard, J. et al. A dynamic upper atmosphere of Venus as revealed by VIRTIS on Venus Express. Nature 450, 641–645 (2007). https://doi.org/10.1038/nature06140
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/nature06140
This article is cited by
-
Venus, the Planet: Introduction to the Evolution of Earth’s Sister Planet
Space Science Reviews (2023)
-
Evaluation of a method to retrieve temperature and wind velocity profiles of the Venusian nightside mesosphere from mid-infrared CO2 absorption line observed by heterodyne spectroscopy
Earth, Planets and Space (2020)
-
Venus Atmospheric Thermal Structure and Radiative Balance
Space Science Reviews (2018)
-
Aeronomy of the Venus Upper Atmosphere
Space Science Reviews (2017)
-
Performance of Akatsuki/IR2 in Venus orbit: the first year
Earth, Planets and Space (2017)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.